Val Logsdon Fitch | Nobel Prize, particle physics, nuclear physics

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js-sections-inline-button module-spacing"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="toc"></em> Table of Contents </button> <button class="ai-ask-button btn border-2 ai-ask-button btn border-2 module-spacing btn-sm js-inline-ai-ask-button btn-outline-red-400 border-red-400 p-10 ml-5"> Ask the Chatbot a Question </button> </div> <div class="js-qf-module qf-module px-40 px-sm-20 py-15 mx-auto module-spacing font-14 bg-gray-50 rounded"> <div class="qf-title font-weight-bold font-14 mb-10 text-center"> Quick Facts</div> <div class="facts-list mt-10"> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Born: </dt> <dd>March 10, 1923, Merriman, <a href="/place/Nebraska-state">Nebraska</a>, U.S.</dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Died: </dt> <dd>February 5, 2015, <a href="/place/Princeton-New-Jersey">Princeton</a>, <a href="/place/New-Jersey">New Jersey</a> (aged 91)</dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Awards And Honors: </dt> <dd><a href="/topic/National-Medal-of-Science">National Medal of Science (1993)</a></dd> <dd><a href="/topic/Nobel-Prize">Nobel Prize (1980)</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Subjects Of Study: </dt> <dd><a href="/science/CP-violation">CP violation</a></dd> <dd><a href="/science/time-reversal">time reversal</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Role In: </dt> <dd><a href="/event/Manhattan-Project">Manhattan Project</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> <div class="text-center"> <a class="btn btn-sm btn-link p-0" href="/facts/Val-Logsdon-Fitch"> See all related content </a> </div> </div> </div> </div><span class="marker before-article"></span><section data-level="1" id="ref1"><span class="marker PREMOD1 mod-inline"></span><p class="topic-paragraph"><strong><span id="ref150919"></span>Val Logsdon Fitch</strong> (born March 10, 1923, Merriman, <a href="https://www.britannica.com/place/Nebraska-state" class="md-crosslink autoxref " data-show-preview="true">Nebraska</a>, U.S.—died February 5, 2015, <a href="https://www.britannica.com/place/Princeton-New-Jersey" class="md-crosslink autoxref " data-show-preview="true">Princeton</a>, New Jersey) was an American particle physicist who was corecipient, with <span id="ref1214998"></span><a href="https://www.britannica.com/biography/James-Cronin" class="md-crosslink " data-show-preview="true">James Watson Cronin</a>, of the <a href="https://www.britannica.com/topic/Nobel-Prize" class="md-crosslink " data-show-preview="true">Nobel Prize</a> for <a href="https://www.britannica.com/topic/Winners-of-the-Nobel-Prize-for-Physics-1856942" class="md-crosslink " data-show-preview="true">Physics</a> in 1980 for experiments conducted in 1964 that disproved the long-held theory that particle interaction should be <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="indifferent" href="https://www.britannica.com/dictionary/indifferent" data-type="EB">indifferent</a> to the direction of time.</p><span class="marker MOD1 mod-inline"></span><span class="marker PREMOD2 mod-inline"></span><p class="topic-paragraph">Fitch’s early interest in chemistry shifted to physics in the mid-1940s when, as a member of the U.S. Army, he was sent to Los Alamos, <a href="https://www.britannica.com/place/New-Mexico" class="md-crosslink autoxref " data-show-preview="true">New Mexico</a>, to work on the <a href="https://www.britannica.com/event/Manhattan-Project" class="md-crosslink " data-show-preview="true">Manhattan Project</a>. He graduated from <a href="https://www.britannica.com/topic/McGill-University" class="md-crosslink autoxref " data-show-preview="true">McGill University</a> in Montreal with a <a href="https://www.britannica.com/topic/bachelors-degree" class="md-crosslink autoxref " data-show-preview="true">bachelor’s degree</a> in electrical engineering in 1948 and was awarded a Ph.D. in physics by <a href="https://www.britannica.com/topic/Columbia-University" class="md-crosslink autoxref " data-show-preview="true">Columbia University</a> in 1954. That year he joined the faculty of <a href="https://www.britannica.com/topic/Princeton-University" class="md-crosslink autoxref " data-show-preview="true">Princeton University</a>, and he later served (1976–81) as chair of its physics department; in 1987 he was named the James S. McDonnell Distinguished University Professor of Physics.</p><div class="one-good-fact-module"> </div><span class="marker MOD2 mod-inline"></span><span class="marker PREMOD3 mod-inline"></span><p class="topic-paragraph">In experiments conducted at the Brookhaven National Laboratory in 1964, Fitch and Cronin showed that the <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="decay" href="https://www.britannica.com/dictionary/decay" data-type="EB">decay</a> of subatomic particles called <span id="ref1215956"></span><a href="https://www.britannica.com/science/K-meson" class="md-crosslink ">K mesons</a> could violate the general <a href="https://www.britannica.com/science/conservation-law" class="md-crosslink autoxref " data-show-preview="true">conservation law</a> for weak interactions known as CP symmetry. Those experiments in turn necessitated physicists’ abandonment of the long-held principle of <span id="ref530565"></span><a href="https://www.britannica.com/science/time-reversal-invariance" class="md-crosslink ">time-reversal invariance</a>. The work done by Fitch and Cronin implied that reversing the direction of time would not precisely reverse the course of certain reactions of subatomic particles. Fitch served on various government bodies, including the President’s Science Advisory Committee (1970–73) and the <a href="https://www.britannica.com/topic/National-Science-Foundation" class="md-crosslink autoxref " data-show-preview="true">National Science Foundation</a> (1980–83), and in 1993 he was awarded the National Medal of Science. (<em>See also</em> <a href="https://www.britannica.com/science/CP-violation" class="md-crosslink " data-show-preview="true">CP violation</a>.) </p><a class="link-module shadow-sm d-block qa-quiz-module" href="/quiz/faces-of-science" data-link-module-iframe-link=""> <img loading="lazy" src="https://cdn.britannica.com/88/144788-131-ADACA20E/Michael-Faraday-John-Frederic-Daniell.jpg" alt="Michael Faraday (L) English physicist and chemist (electromagnetism) and John Frederic Daniell (R) British chemist and meteorologist who invented the Daniell cell." class="rounded-sm mr-15" width="70" /> <div class="line-clamp clamp-5"> <div class="module-title bg-green">Britannica Quiz</div> <div class="font-weight-semi-bold mt-5">Faces of Science</div> </div> </a><span class="marker MOD3 mod-inline"></span></section> <span class="md-signature">This article was most recently revised and updated by <a href="/contributor/encyclopaedia-britannica/12989892">Encyclopaedia Britannica</a>.</span><span class="marker end-of-content"></span><span class="marker after-article"></span></div> <div id="chatbot-root"></div> </div> </div> </div> <div class="ai-dialog-placeholder"></div> </div> </div> <aside class="col-md-da-320"></aside> </div> </div> </div> </div> </article></div> </div></div> </div> </main> <div id="md-footer"></div> <noscript><iframe src="//www.googletagmanager.com/ns.html?id=GTM-5W6NC8" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript> <script type="text/javascript" id="_informizely_script_tag"> var IzWidget = IzWidget || {}; (function (d) { var scriptElement = d.createElement('script'); scriptElement.type = 'text/javascript'; scriptElement.async = true; scriptElement.src = "https://insitez.blob.core.windows.net/site/f780f33e-a610-4ac2-af81-3eb184037547.js"; var node = d.getElementById('_informizely_script_tag'); node.parentNode.insertBefore(scriptElement, node); } )(document); </script>  <script> window.ap3c = window.ap3c || {}; var ap3c = window.ap3c; ap3c.cmd = ap3c.cmd || []; ap3c.cmd.push(function() { ap3c.init('ZO4siT4cLwnykPnzZWJtd3Byb2Q', 'https://engage.email.britannica.com/'); ap3c.track({v: 0}); }); ap3c.activity = function(act) { ap3c.act = (ap3c.act || []); ap3c.act.push(act); }; var s, t; s = document.createElement('script'); s.type = 'text/javascript'; s.src = "https://engage.email.britannica.com/app.js"; t = document.getElementsByTagName('script')[0]; t.parentNode.insertBefore(s, t); </script> <script class="marketing-page-info" type="application/json"> {"pageType":"Topic","templateName":"DESKTOP","pageNumber":1,"pagesTotal":1,"pageId":208851,"pageLength":249,"initialLoad":true,"lastPageOfScroll":false} </script> <script class="marketing-content-info" type="application/json"> [] </script> <script src="https://cdn.britannica.com/mendel-resources/3-130/js/libs/jquery-3.5.0.min.js?v=3.130.14"></script> <script type="text/javascript" data-type="Init Mendel Code Splitting"> (function() { $.ajax({ dataType: 'script', cache: true, url: 'https://cdn.britannica.com/mendel-resources/3-130/dist/topic-page.js?v=3.130.14' }); })(); </script> <script class="analytics-metadata" type="application/json"> {"leg":"C","adLeg":"C","userType":"ANONYMOUS","pageType":"Topic","pageSubtype":null,"articleTemplateType":"BIO_SMALL","gisted":false,"pageNumber":1,"hasSummarizeButton":false,"hasAskButton":false} </script> <script type="text/javascript"> EBStat={accountId:-1,hostnameOverride:'webstats.eb.com',domain:'www.britannica.com', json:''}; </script> <script type="text/javascript"> ( function() { $.ajax( { dataType: 'script', cache: true, url: '//www.britannica.com/webstats/mendelstats.js?v=1' } ) .done( function() { try {writeStat(null,EBStat);} catch(err){} } ); })(); </script> <div id="bc-fixed-dialogue"></div> </body> </html>

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Val Logsdon Fitch | Nobel Prize, particle physics, nuclear physics | Britannica